Electronics manufacturers, cable service providers, and multiple system operators (MSOs) strive to provide products that are energy efficient in order to save money for customers and to meet governmental regulations. The voluntary Energy Star rating of the U.S. Environmental Protection Agency (EPA) is an example of such a regulation. In order to earn an Energy Star label, products are certified by a third-party organization based on testing in EPA-recognized laboratories.
A popular electronic apparatus in many homes is the so called “set-top box” which houses electronic circuits that convert signals from an input line into signals usable by consumer devices for displaying data and audio/video media content such as television programing and movies. The types of consumer devices being served by set-top boxes will become more varied, including not only televisions, but computers, and portable devices such as electronic tablets and smart phones. The input signals can be provided by service providers including cable television providers, satellite television providers, internet service providers, and multiple system operators. In addition to being provided in the self contained set-top box configuration, the electronics can be integrated directly into the consumer device, such as being built into a television. For ease of discussion, the set-top box configuration will be referred to hereafter, but the invention is not intended to be limited only to set-top boxes.
To determine the most effective approach for power savings for a set-top box it is necessary to analyze the allocation of power consumption by the various functions provided by the apparatus. In addition to basic cable television functions and/or Internet Protocol Television (IPTV) functions, the set-top boxes disclosed herein may include computer network connectivity functions, including Local Area Network (LAN) interfaces, and Wireless Local Area Network (WLAN) interfaces which use wireless signals, such as Wi-Fi or in-home LTE (Long Term Evolution) technology, or the like. Network interfaces are high power consumption features on a set-top box.
In order to achieve the maximum level of savings it has been found by the inventors that it is necessary to power down all of the network interfaces of the set-top box. For ease of installation and maximization of potential locations in the home, the set-top boxes disclosed herein are not required to be connected to the home network via a wired connection, but rather may exclusively use a Wi-Fi connection. In the case of such a Wi-Fi-only set-top box, to power down the network interface the Wi-Fi radio must be powered down. The radio on a Wi-Fi only set-top box is responsible for approximately 50% of the power consumption of the device. Typical power consumption of a Wi-Fi radio can be anywhere between 2 and 3 watts, even in a receive-only mode, and higher in a full transmission mode.
The set-top box can be put into a low power mode in which the Wi-Fi radio and WLAN interface are powered down. A set-top box in such a low-power mode can be quickly brought back up to full operational mode via a user input, such as by a button being pushed on the set-top box by the user. However such a manual operation is not suitable in many instances. For example, service providers typically perform remote management operations, such as code downloads and software upgrades, during non-peak off hours, such as during the over night and early morning hours while most customers are asleep. For example, most set-top boxes are not in use during the period of time between 12:00 AM and 7:00 AM.
Wake on LAN (WoL) is a networking operation that allows a network connected device to be turned on or awakened via a network message. The message is usually sent by another computer or device on the same local area network. It is also possible to initiate the message from another network outside the local area network, such as by using subnet directed broadcasts or by a WoL gateway service. When the device being awakened is communicating via Wi-Fi, a supplementary standard called Wake on Wireless LAN (WoWLAN) must be employed. However, Wake on LAN and Wake on Wireless LAN require the radio to be marginally operational in order for the feature to work. Therefore, relying on WoL and WoWLAN for waking a set-top box for service provider management operations would negate expected power savings because the Wi-Fi radio would need to remain in some marginal operation state such as a receive only mode. Because of these drawbacks of existing technologies, there is a need to wake a Wi-Fi-only set-top box while it is in a low power mode in which the Wi-Fi radio is powered down.